OceanCanada Contributor: Lam VWY

Climate change impacts on marine biodiversity, fisheries and society in the Arabian Gulf.

Posted on by d.burnside

Climate change–reflected in significant environmental changes such as warming, sea level rise, shifts in salinity, oxygen and other ocean conditions–is expected to impact marine organisms and associated fisheries. This study provides an assessment of the potential impacts on, and the vulnerability of, marine biodiversity and fisheries catches in the Arabian Gulf under climate change. To this end, using three separate niche modelling approaches under a ‘business-as-usual’ climate change scenario, we projected the future habitat suitability of the Arabian Gulf (also known as the Persian Gulf) for 55 expert-identified priority species, including charismatic and non-fish species. Second, we conducted a vulnerability assessment of national economies to climate change impacts on fisheries. The modelling outputs suggested a high rate of local extinction (up to 35% of initial species richness) by 2090 relative to 2010. Spatially, projected local extinctions are highest in the southwestern part of the Gulf, off the coast of Saudi Arabia, Qatar and the United Arab Emirates (UAE). While the projected patterns provided useful indicators of potential climate change impacts on the region’s diversity, the magnitude of changes in habitat suitability are more uncertain. Fisheries-specific results suggested reduced future catch potential for several countries on the western side of the Gulf, with projections differing only slightly among models. Qatar and the UAE were particularly affected, with more than a 26% drop in future fish catch potential. Integrating changes in catch potential with socio-economic indicators suggested the fisheries of Bahrain and Iran may be most vulnerable to climate change. We discuss limitations of the indicators and the methods used, as well as the implications of our overall findings for conservation and fisheries management policies in the region.

Regional variability in the sensitivity of Caribbean reef fish assemblages to ocean warming.

Posted on by d.burnside

Ocean warming is expected to impact biodiversity and fisheries in the tropics through shifts in species’ distributions, leading to local extinctions and changes in species composition of catches. However, regional-scale patterns may differ from global trends due to the influence of important environmental factors such as ocean warming, fishing and habitat availability. Here, we used the mean temperature of the catch to test the hypothesis that, for the period of 1971 to 2010, regional variation in species-turnover of exploited reef fish assemblages among 9 Caribbean countries can be explained by differences in the rate of warming, species’ thermal preferences, changes in trophic structure due to fishing and potential reef habitat across the region.

Ex-vessel fish price database: disaggregating prices for low-priced species from reduction fisheries.

Posted on by d.burnside

Ex-vessel fish prices are essential for comprehensive fisheries management and socioeconomic analyses for fisheries science. In this paper, we reconstructed a global ex-vessel price database with the following areas of improvement: (1) compiling reported prices explicitly listed as “for reduction to fishmeal and fish oil” to estimate prices separately for catches destined for fishmeal and fish oil production, and other non-direct human consumption purposes; (2) including 95% confidence limit estimates for each price estimation; and (3) increasing the number of input data and the number of price estimates to match the reconstructed Sea Around Us catch database. Our primary focus was to address this first area of improvement as ex-vessel prices for catches destined for non-direct human consumption purposes were substantially overestimated, notably in countries with large reduction fisheries. For example in Peru, 2010 landed values were estimated as 3.8 billion real 2010 USD when using separate prices for reduction fisheries, compared with 5.8 billion using previous methods with only one price for all end-products. This update of the price database has significant global and country-specific impacts on fisheries price and landed value trends over time.

Global seafood trade flows and developing economies: insights from linking trade and production.

Posted on by d.burnside

Knowing the patterns of marine resource exploitation and seafood trade may help countries to design their future strategic plans and development policies. To fully understand these patterns, it is necessary to identify where the benefits accumulate, how balanced the arrangements are, and how the pattern is evolving over time. Here the flow of global seafood was traced from locations of capture or production to their countries of consumption using novel approaches and databases. Results indicate an increasing dominance of Asian fleets by the volume of catch from the 1950s to the 2010s, including fishing in the high seas. The majority of landings were by high-income countries’ fishing fleets in their own waters in the 1950s but this pattern was greatly altered by the 2010s, with more equality in landings volume and value by fleets representing different income levels. Results also show that the higher the income of a country, the more valuable seafood it imports compared to its exports and vice versa. In theory, this implies that the lower income countries are exporting high value seafood in part to achieve the broader goal of ending poverty, while achieving the food security goal by retaining and importing lower value seafood. In the context of access arrangements between developed and developing countries, the results allow insights into the consequences of these shifting sources of income may have for goals such as poverty reduction and food security.

Economic challenges to the generalization of integrated multi-trophic aquaculture: an empirical comparative study on kelp monoculture and kelp-mollusk polyculture in Weihai, China.

Posted on by d.burnside

With the rapid growth of aquaculture, some negative factors of extensive monoculture accumulated, causing integrated multi-trophic aquaculture (IMTA) to draw increasing attention worldwide for its ecological and economic advantages. However, the development of IMTA in open water systems may not go as smoothly as anticipated—at least in Weihai, China, some producers who have adopted it would prefer to return to monoculture. This paper explores the problem from the angle of the economic performance by providing an in-depth analysis of costs and revenues generated by kelp monoculture and kelp-mollusk polyculture (IMTA). We find that the monoculture generates higher profits during the same production cycle. Besides inherent defects in system design, the rapidly growing labor cost and depressing selling price of the mollusk conspire to aggravate the economic failure of IMTA. Due to positive environmental externalities, the social benefits associated with IMTA are higher than the private benefits. This implies that there is a role for the government to generalize IMTA to achieve more total benefits. But single policy such as subsidies may backfire, a combination of policies designed to promote IMTA could be effective.

Impact of high seas closure on food security in low income fish dependent countries.

Posted on by d.burnside

We investigate how high seas closure will affect the availability of commonly consumed food fish in 46 fish reliant, and/or low income countries. Domestic consumption of straddling fish species (fish that would be affected by high seas closure) occurred in 54% of the assessed countries. The majority (70%) of countries were projected to experience net catch gains following high seas closure. However, countries with projected catch gains and that also consumed the straddling fish species domestically made up only 37% of the assessed countries. In contrast, much fewer countries (25%) were projected to incur net losses from high seas closure, and of these, straddling species were used domestically in less than half (45%) of the countries. Our findings suggest that, given the current consumption patterns of straddling species, high seas closure may only directly benefit the supply of domestically consumed food fish in a small number of fish reliant and/or low income countries.

Projected change in global fisheries revenues under climate change.

Posted on by d.burnside

Previous studies highlight the winners and losers in fisheries under climate change based on shifts in biomass, species composition and potential catches. Understanding how climate change is likely to alter the fisheries revenues of maritime countries is a crucial next step towards the development of effective socio-economic policy and food sustainability strategies to mitigate and adapt to climate change. Particularly, fish prices and cross-oceans connections through distant water fishing operations may largely modify the projected climate change impacts on fisheries revenues. However, these factors have not formally been considered in global studies. Here, using climate-living marine resources simulation models, we show that global fisheries revenues could drop by 35% more than the projected decrease in catches by the 2050 s under high CO2 emission scenarios. Regionally, the projected increases in fish catch in high latitudes may not translate into increases in revenues because of the increasing dominance of low value fish, and the decrease in catches by these countries’ vessels operating in more severely impacted distant waters. Also, we find that developing countries with high fisheries dependency are negatively impacted. Our results suggest the need to conduct full-fledged economic analyses of the potential economic effects of climate change on global marine fisheries.

Transform high seas management to build climate resilience in marine seafood supply.

Posted on by d.burnside

Climate change is projected to redistribute fisheries resources, resulting in tropical regions suffering decreases in seafood production. While sustainably managing marine ecosystems contributes to building climate resilience, these solutions require transformation of ocean governance. Recent studies and international initiatives suggest that conserving high seas biodiversity and fish stocks will have ecological and economic benefits; however, implications for seafood security under climate change have not been examined. Here, we apply global-scale mechanistic species distribution models to 30 major straddling fish stocks to show that transforming high seas fisheries governance could increase resilience to climate change impacts. By closing the high seas to fishing or cooperatively managing its fisheries, we project that catches in exclusive economic zones (EEZs) would likely increase by around 10% by 2050 relative to 2000 under climate change (representative concentration pathway 4.5 and 8.5), compensating for the expected losses (around −6%) from ‘business-as-usual’. Specifically, high seas closure increases the resilience of fish stocks, as indicated by a mean species abundance index, by 30% in EEZs. We suggest that improving high seas fisheries governance would increase the resilience of coastal countries to climate change.

Global fisheries subsidies: an updated estimate.

Posted on by d.burnside

The aim of this paper is to provide an updated estimate of global fisheries subsidies. It builds on earlier estimates and methodologies to re-estimate and discuss the various types of subsidies provided by governments around the world. The results suggests that total subsidies were about USD 35 billion in 2009 dollars, which is close to the earlier estimate of 2003 subsidies once they are adjusted for inflation. Capacity-enhancing subsidies constituted the highest category at over USD 20 billion. For all regions, the amount of capacity-enhancing subsidies is higher than other categories, except for North America, which has higher beneficial subsidies. The analysis reveals that fuel subsidies constitute the greatest part of the total subsidy (22% of the total), followed by subsidies for management (20% of the total) and ports and harbors (10% of the total). Subsidies provided by developed countries are far greater (65% of the total) than those by developing countries (35% of the total) even though the latter lands well above 50% of total global catch. Asia is by far the greatest subsidizing region (43% of total), followed by Europe (25% of total) and North America (16% of total). Japan provides the highest amount of subsidies (19.7% of total), followed by the United States and China at 19.6% of total.

Out of stock: the impact of climate change on British Columbia’s staple seafood supply and prices.

Posted on by d.burnside

Highlights:
• Ocean physics and chemistry is being affected significantly by carbon dioxide (CO2) emissions, impacting key  marine and coastal organisms, ecosystems and the services they provide us, including seafood.
• These impacts will occur across all latitudes, including in the waters of British Columbia and Canada. This will have
direct impacts on the fish species that are consumed by residents of B.C.
• The supply of B.C.’s “staple seafood” species such as Pacific salmon (e.g., sockeye and chum), Pacific halibut, groundfish species (e.g. sablefish), Pacific hake, crabs and prawns will be affected.
• This study predicts that by 2050:

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